Managing the lifetimes of garbage-collected objects [closed]
Managing the lifetimes of garbage-collected objects [closed]
garbage-collection
Do you need to dispose of objects and set them to null?
Objects will be cleaned up when they are no longer being used and when the garbage collector sees fit. Sometimes, you may need to set an object to null in order to make it go out of scope (such as a static field whose value you no longer need), but overall there is usually no … Read more
Java heap terminology: young, old and permanent generations?
This seems like a common misunderstanding. In Oracle’s JVM, the permanent generation is not part of the heap. It’s a separate space for class definitions and related data. In Java 6 and earlier, interned strings were also stored in the permanent generation. In Java 7, interned strings are stored in the main object heap. Here … Read more
When should I use GC.SuppressFinalize()?
SuppressFinalize should only be called by a class that has a finalizer. It’s informing the Garbage Collector (GC) that this object was cleaned up fully. The recommended IDisposable pattern when you have a finalizer is: public class MyClass : IDisposable { private bool disposed = false; protected virtual void Dispose(bool disposing) { if (!disposed) { … Read more
Why is it bad practice to call System.gc()?
The reason everyone always says to avoid System.gc() is that it is a pretty good indicator of fundamentally broken code. Any code that depends on it for correctness is certainly broken; any that rely on it for performance are most likely broken. You don’t know what sort of garbage collector you are running under. There … Read more
When is the finalize() method called in Java?
The finalize method is called when an object is about to get garbage collected. That can be at any time after it has become eligible for garbage collection. Note that it’s entirely possible that an object never gets garbage collected (and thus finalize is never called). This can happen when the object never becomes eligible … Read more
Deleting Objects in JavaScript
The delete operator deletes only a reference, never an object itself. If it did delete the object itself, other remaining references would be dangling, like a C++ delete. (And accessing one of them would cause a crash. To make them all turn null would mean having extra work when deleting or extra memory for each … Read more
Where Is Machine.Config?
32-bit %windir%\Microsoft.NET\Framework\[version]\config\machine.config 64-bit %windir%\Microsoft.NET\Framework64\[version]\config\machine.config [version] should be equal to v1.0.3705, v1.1.4322, v2.0.50727 or v4.0.30319. v3.0 and v3.5 just contain additional assemblies to v2.0.50727 so there should be no config\machine.config. v4.5.x and v4.6.x are stored inside v4.0.30319.
Is there a destructor for Java?
Because Java is a garbage collected language you cannot predict when (or even if) an object will be destroyed. Hence there is no direct equivalent of a destructor. There is an inherited method called finalize, but this is called entirely at the discretion of the garbage collector. So for classes that need to explicitly tidy … Read more
Error java.lang.OutOfMemoryError: GC overhead limit exceeded
This message means that for some reason the garbage collector is taking an excessive amount of time (by default 98% of all CPU time of the process) and recovers very little memory in each run (by default 2% of the heap). This effectively means that your program stops doing any progress and is busy running … Read more